A known system is provided with a generator that is connected to a converter which, in turn, is connected to an energy supply grid. The frequency of the voltage generated by the generator is variable. A plurality of different switch positions can be realized with the converter.
This system can be used to connect an energy producer, for example a wind electrical energy plant, to a public three-phase grid. The wind electrical energy plant operates the generator with a variable speed. The frequency of the voltage generated by the generator is thus also variable and must be adapted to the substantially constant frequency of the three-phase grid, achievable with the aid of the converter. Numerous controls and/or adjustments are known for these converters.